"Fuehlometer" (Feel-o-meter) or "Public Face" is an interactive art installation that shows the mood of a city by displaying it in the form of a monumental Smiley. The system allows to read emotions out of random people's faces. The faces are analyzed by sophisticated software (contributed by the Fraunhofer Institut). The obtained mood data are then stored on a server and processed by the smiley to visualize the emotions in real-time.

Here's the piece on display in 2010 at Lindau Island in Germany. Could these be established across the land as public indicators of the National Happiness Index?